Electrical measuring instrument.



W. E. PORTER, ELECTRICAL MEASURING INSTRUMENT.

APPLICATlON FILED SEPT-25. 1914.

FKgS.

lnvenbofi VWHaFd E.DoFte Patented Sept. 28, 1915.

2 SHEETS-SHEET! vwpnessesz W. E. PORTER.

ELECTRICAL MEASURING INSTRUMENT.

APPLICATUON H LED SEPT-25, 1914.

1,155,095. Patented Sept. 28, 1915.

2 SHEETS-SHEET 2.

Witnesses: Inventor fave fl7dn WIIIar-d E. Dots UNITED s rn'r ts rares Ga a WILLARD E. YORTER, CF LYNN, LIASSACHUSETTS, ASSIGHOE TO GENERAL ELEGTRIG COLIPANY, A COEPORATIQZI 0F LIEXV YORK.

ELECTRICAL MEASURING INSTRUMENT.

Application filed September 2'5, 1514.

To all whom it may concern- Be it known that I, WILLARD E. loarniz, a citizen of the United States, residing at Lynn, county of Essex, State of Massachw setts, have invented certain new and useful Improvements in Electrical Measuring Instrume nts, of which the following is a specification.

My invention relates to electrical measuring instruments, and particularly to coun-- terbalancing devices for the moving element of electrical measuring instruments,

The object of my invention is to provide a novel and improved construction of counter balancing device for the moving element of an electrical measuring instrument.

More particularly the object of my invention is to provide a simple, inexpensive and reliable means for securing a counterweight or a. cross counterhalancing arm to the moving element of such an instrument, and further such means for securing both it counterweight and a cross counterbalancing arm to the moving element.

The novel features of my invention which I believe to be. patentable and upon which I desire to secure Letters Patent are definitely indicated in the claims appended 'her to. The principle of my invcnti' i. and its em hodiment in the moving element of an cl trical measuring instrument will-he under-- stood from the loliowing description taken in connection with the accompanying drawings in which:

Figure l is a perspective View of the mov ing element of an electrical measuring in strument embodying my invention; l igs. 2 and 3 are detail views of the counterbalancing device of the moving elen'ient shown in Fig. 1; Figs. 4, 6, 8 and 10 are perspective views of modified forms of the invention; and Figs. 5, 7, 9 and ii are detail sectional views on the section lines 5--5, 7?, 9-9

and 1l11 of Figs. i, 6, 8 and 10, respectively.

T he moving element of'an electrical measuring instrument should usually have two counterbalance adjustments substantially at right angles to each other in eiiect Gen- Speciiicstion of Letters Patent.

Serial No. 853,475.

erally the counterbalance adjustments are e'tl'ected by two counterbalancing devices, a side or cross balancing arm to counterbalance inequalities in the symmetry of each side of the moving element, and a counterbalancing device or counterweight to countel-balance for the pointer, damping, or other analogous member of the moving element. In accordance with my present invention, the side or cross balancing arm is firmly secured to the moving element in a novel and improved manner by the action eta spring member. I further provide a novel and improved construction whereby the same spring member serves to firmly seci e the counterweight to the moving element. Preferably, and asa matter of practice generally, the cross balancing arm and the counterweight are adjustable, and iii-accordance with the novel and improved construction of my present invention, the adjust: 1. of each of these counterbalancing devices may be conveniently and accurately acco lilishod. g

H "ention will be best understood by re... to the accompanying drawings. l l of the drawings shows the moving element of an eiectricalYmeasuring instrument of the well known inclined coil type. 15 having pivot pins at each end :res to pivot-ally mount the moving element in the jewels or other bearings of the instrument in the well understood manner. The shaft carries the usual. metallic vanes 16 and an air damping member 17. A pointer member 18 extends transversely through. the shaft and is rigidly secured thereto. The pointer member has at one end an indicating vane 19 and at the other end a counterweight 20. The counterweight 20 is in the form of a check or lock nut having two symmetrically positioned slots or saw cuts. 1

A hole 21 extends transversely through or the diameter of the hole 21 may be slightly greater than that of the arm 22 and not screw-threaded, in which case the arm may be freely moved through the hole. A leaf or flat spring member 23 having a hole intermediate its ends through which the shaft 15 extends is loosely positioned be tween the member 18 and the side balancing arm 22. The extremities of the spring 23 are notched and bear against the member 18, as clearly shown in Fig. 3 of the drawings, while the intermediate or middle portion of the spring exerts a force or pressure against the side balancing arm 22. The action of the spring is to firmly hold the arm in the hole'21 of the shaft. The arm 22 may be conveniently turned "or moved for adjustment by means of a nut 24 secured thereto. It will thus be observed that the spring in effect braces itself against the relatively rigid member 18 and exerts its spring action against the arm 22, whereby the arm is firmly secured to the moving element in its desired adjusted position.

In Figs. 4, 6 and 8 of the drawings, I have illustrated my novel and improved means for securing both counterbalancing devices ,to the moving element by the action of a.

single spring. In the construction shown in these figures the shaft 15, pointer member 18' and side balancing arm 22 are correlated exactly as in the construction shown in Fig. 1. The pointer member 18 is, however, hollow, or may have only a hollow portion at one end, and a counterweight arm 25 is adapted to extendvfreely and loosely within the member. .A nut is threaded on a screw-threaded portion of the arm 25 and is held in a relatively fixed position with respect to the moving element by the action of a flat leaf spring member, one end of the latter bearing against the nut. In Figs. 4 and 6, I have shown a leaf spring member 23 having a notch at one end and a hole 26 at the other end. In Figs. 4 and 5, I have shown a round nut 27 engaging in the hole 26 of the spring 23, while in Figs. 6 and 7 I haveshown a. square nut 28 engaging in the hole. It will be observed that where the round nut 27 is employed the hole 26 is rectangular, as indicated in Fig.4, while this hole may be circular where the square nut 28 is employed, as indicated in Fig. 6. In Fig. 8, the spring 23 is provided at one end with ears 29 which engage in substantially diametrically opposite sections of a peripheral groove 30 in a round nut 31.

It will be observed in each of the three modifications shown in Figs. 4, 6 and 8 that the nut 27, 28 or 31, as the case may be, is firmly held in position by the action of the flat spring. The counterweight arm may thus be threaded through the relatively fixed nut to secure the desired adjustment. In

Figs. 4, 6 and 8, I have shown the ends of other irregular shaped ends 32. A suitable wrench may then be employed to turn the arm for adjusting'purposes.

In fig. 8 of the drawings, I have shown an additional counterweight 33 .secured to the counterweight arm 25. The' counterweight 33 is conveniently made out of a piece of brass rod, drilled and split lengthwise. The dimensions are such that the counterweight 33 can be readily pushed on one end of the counterweight arm 25, which, it will be observed, is not threaded at its ends. The counterweight 33 opens up slightly when it is pushed on the arm 25, and the spring of the stock holds it firmly in position. The split. counterweights 33 are made in various sizes, and one of the proper weight for an approximate balance is placed on the arm 25. The fine adjustment for exact counterbalancing is then obtained by screwing the arm 25 through its cooperating nut.

In Fig. 10, I have shown the counterbalancing device secured to a damping disk 34 of a moving element particularly adapted for an electricalmeasuring instrument of the type disclosed in the patent application filed on behalf of myself and Alvarado L. R. Ellis, May 16, 1914, Serial Number 836,647. The damping disk is mounted upon a shaft 35 provided with the usual pivot points. A pointer member 36 is secured to one side of the damping disk 34, and the counterbalancing device is adjustably mounted on the diametrically opposite side of the disk. The counterbalancing device comprises a spring clip 37 having two ears or projections 38 extending through a circular hole 39 in the disk. The length of the spring clip is greater than the diameter of the hole 39, and

movement of the clip through the hole in one direction is thus prevented- The projections 38 are provided with apertures in which a screw-threaded counterbalancing arm 40 is operatively positioned. The material of the projections is so thin that the threads on the counterbalancing arm 40 are engaged thereby, thus eliminating the necessity of threading the apertures. The arms of the spring clip 37 contact with the disk 34'and exert a spring tension tending to pull the projection 38 back through thehole 39, Which'at once serves to hold the spring clip and the counterbalancing arm definitely in position, but permits the ready adjustmentof each of these members. By turning the spring clip, the entire counterbalancing de vice may be rotated in the hole 39, and by turning the counterbalancing arm 40, the

. weight arm 25 flattened to provide square or position of the arm with respect to the.

spring clip can be altered. These two move- 4 pi'mliie the muvssnry ccmutcrbalanw iulizmiiwnia it will ba- 50011 that the i in willlwmcvs itself against in 0f the (il5iil 3+ and its spring tendi f: the (1mmlei-balancing arm against Y ilhl side hf the disk tlins firmly secur in}; ilii :mi: \Yiili IQSpQi'i in the disk and the .Plifiklfill'fi.

mwl UUHSU'UCUOH of counterbalancwe of my pi'esieni invention possesses 'l'miwwing pmtivuliu' 21d 'antages ww in; H5 inratzmt adjustmentwitl out uni (in delicate: li'lllflllllQS SIDRll *simplicity (if parts,

pmr ill LPQHF. iiiquirizu;-lightnnss; HlJllllY iu mai-ly all types of instruments.

av wt oleirtiicnl measuring instrue have a final adjustment after and with Llm easy friction lock of aiinn, l0; can" DQOQSRH) in this iiiijllllilllPn-i. to gwment injury to tho 7 pails Of tlic instrument than. in any alumni-inaiming device knnwn ,tn me. ill countei-lzilana'cing devices of iwllii L l mew linuwlmlgumnsidu'nble exactness: is iiwmsnry to make cmmtei'weiglit nuts and mvls inn l'mngmil le. In my construclfill rnniiii'lwrulile more margin can be zilloixwl i ilii iiirs rlion.

ii, iii.

he, olisnrwi'l i-um tin: mil /going ilesmilplmn that l 132ml pirm'nlwii an (X-- simple coi'istrm-iiun Zl m ;i: ultaneonsly securing twn .wmwlmlzuicing (lei the moving ir'riztil'wlii of m QlQCU'lCZXl in liumeiit ii ili mfilfill :2 a T ialwr. film" 313%; miznil'mi li'ii ilnililil l aim: in iii-w exerted aimiiic'l the arm in: is lim'ily i'nzlil against a 21min ulunienh in all nun of: my present invention. It will fur ind adapt-i art that the ;--yrirs; men l l) 211' directly 0n {lie lil'ii'm cuuntcrweiglit am: 353 as well a rough aha action bf an independent nut which in fest amounts to making ilie nut {iii an up erative elmnent in the ciunlniimiii ii integral with the spring;

It will of cum-5:0 be UXHlUISLOOil iilmi; film foregoing description and acccjnnpanying illustrations are: mainly fur the purpuw. explaining Hi0 priniiple r? in Nliillti-IUHS pflltillf'fil ('Hlbfiiiiilii" v venfiion in illL liwviiigg (liilhiiii is"? typi-s 0f clem's-iarzil mmsuring in? will be Wis mi in H1051 :iiillifli in i1 u} a. I flfijlbfilll'igly (in nux w ii m be resti'ini, to the Pzillltillzlf ("'ISlmifllifiiiliifs' (lint-l0: herein, by way c QK HEplQ for ilie pmpese of setting im-tli my lflwflii m in 210 34; :(1111160 with the patent stnintma f'hs im'in the zqipendod claims, llim'afni'u r m illblf flCt tlioimnr'n in? evident in 7 i ml to the: pl'mfl lii stm z'i'm'ias ii ,lnsezl but are intended in 151" Zill mm m Lions williizz the pi it :1 vention.

What I claim as u mm by Leila-Q Pawn: of the l 1. In U1 ('ltutli the conilt inaitinn 1 2 mm: at (if a counterlmlarming; Hi l. a i-wimm v arm, and a, spring 03*; 'zi'ivuly i'lzlan'ed in (will element and zujlriptu n iirii' )2 i iain said counter-bah)lining it numer- Weight arm in tin-ii r 1 i Fits m; is ill lllt,

wgli of f. li iwie gz lzt in: .mglm

n 3 ex in izzmli 0%., a

p m 9 um Y i ilni: Winn min m win 11 lllifi. m ni i iIWU 00 1mm H stzuiiinlly all ,lil a spring: mi'iiml by said Ml to bfliilifi: iziiifll of wicl iilmp position with 1 .1) ilia element.

5. in an (-tlQCli waxy-wing insci'umnnt, the mmbiimtinnwith :1 n'im'i lila member having a l iiiggiimlinnl ink: in, uilC- mail tlwrw of, of a (7OL1IltQlWl$2TlilI :ii'm adapted it) exiii) tend into said hole, a nut threaded on said arm, and resilient means for maintaining the nut in a fixed position with respect to said member.

6. In an electrical measuring instrument, the combination with a movable element of a counterweight arm, a nut threaded on said arm, and a spring operatively secured to said element and adapted to maintain the nut in a fixed position with respect to said element.

7. In an electrical measuring instrument, the combination with a movable member of a counterbalancing arm, and a flat spring having its ends bearing against said member and exerting a force on said arm to hold said arm in an adjusted position with respect to said member.

8. In an electrical measuring instrument, the combination with a movable shaft having a transverse hole therein of a counterbalancing arm positioned in said hole, a member secured to said shaft in a position substantially at right angles to said arm, and a spring resting against said member and exerting a force on said arm to securely hold the arm in its adjusted position in the hole in said shaft.

9. In an electrical measuring instrument, the combination with a movable element of a counterbalancing arm, and a spring braced against a rigid member of said ele; ment and adapted to exert a force on said arm to firmly hold the arm against a rigid part of said element.

10. In an electrical measuring instrument the combination with a moving element of a counterbalancing arm, and a flat spring braced against a rigid member of said element and adapted to exert a force on said arm to firmly hold the arm against a second rigid member of said element.

11. In an electrical measuring instrument, the,combination with a movable shaft having a transverse hole therein of a counterbalancing arm positioned in said hole, a member secured to said shaft in a position substantially at right angles to said. arm,

and a spring braced against said member and exerting a force against said arm whereby the arm is forced firmly against the wall of the hole in said shaft.

12. In an electrical measuring instrument, the combination-with a movable shaft having a transverse hole therein of a counterbalancing arm positioned in said hole, a pointer member secured to said shaft substantially at right angles to said arm, and a at spring having a hole through which said shaft freely extends and having itsends resting against said member whereby the spring exerts a force on said arm to hold the arm firmly in the hole in said shaft.

13. In an electrical measuring instrument,

the combination with a movable shaft having a transverse hole therein of a counterbalancing arm extending through said hole, a member secured to said shaft substantially at right angles/to and a short distance from said arm, and a flat spring positioned between said arm and said member and havin its ends resting against said member an an intermediate portion acting against said arm to firmly hold the arm in the hole in said shaft.

14. In an electrical measuring instrument the combination with a movable shaft having a transverse hole therein of a counterbalancing arm extending through said hole, a member secured to said shaft substantially at right angles to and a short distance from said arm, said member having a longitudinal hole in one end, a counterweight arm extending into the hole in said member, a nut threaded on said counterweight arm, anda fiat spring having one end resting against said member and the other end resting against said nut and an intermediate portion acting against said counter-balancing arm, whereby the nut is maintained in a relatively fixed position and the counterbalancing arm is firmly held in the hole in said shaft.

15. In an electrical measuring instrument, the combination with a movable element of a counterweight arm, and a spring having one end bearing against a rigid member of said element and the other end operatively bearing against said counterweight arm.

16. In an electrical measuring instrument, the combination with a movable member having a longitudinal hole in one end thereof, of a counterweight arm adapted to extend into said hole, and a spring for maintaining said counterweight arm in its proper position.

. 17. In an electrical measuring instrument, the combination with a movable element having a longitudinal hole in one end thereof, of a counterweight arm adapted to extend into said hole, and a spring having one end bearing against said member and the other end operatively bearing against said counterweight arm and adapted to maintaih said counterweight arm in its proper position.

18. In an electrical. measuring instrument, the combination: with a movable shaft having a transverse hole therein of a counterbalancing arm extending through said hole, a member secured to said shaft substantially at right angles to and a short distance from said arm, said member having a longitudi nal hole in one end, a counterweight arm adapted to freely move in the hole in said member and having a screw threaded portion, a nut threaded on said counterweight arm, and a flat spring having an aperture through which said shaft extends and positioned between said counterbalancing arm and said member with one end resting against mid member and the other end resting; against said nut and an intermediate portion acting against said counterbalancing arm whereby the nut is nmintained in a relatively fixed position. and the eouuterbalancing arm is firmly held in the hole in said shaft.

In Witness whereof, I have hereunto set my hand thisQ-ith day of September 1914. WILLARD E. PORTER. \Vitnesses:

BENJAMIN B. HULL, MERTON W. SAGE. 

